using System.Diagnostics;
using System.Net;
using System.Reflection;
using HarmonyLib;
using PluginLoader.Compiler;
using PluginLoader.Data;
using PluginLoader.GUI;
using PluginLoader.Stats;
using Sandbox.Game.World;
using VRage.Plugins;
using SEPMPlugin = PluginLoader.SEPM.SEPMPlugin;

namespace PluginLoader;

public class Main : IHandleInputPlugin
{
    private const string HarmonyVersion = "2.2.1.0";

    public static Main Instance;

    private readonly List<PluginInstance> plugins = new();

    private bool init;

    public Main()
    {
        var sw = Stopwatch.StartNew();

        Splash = new();

        Instance = this;

        var temp = Cursor.Current;
        Cursor.Current = Cursors.AppStarting;

        var pluginsDir = LoaderTools.PluginsDir;
        Directory.CreateDirectory(pluginsDir);

        LogFile.Init(pluginsDir);
        LogFile.WriteLine("Starting - v" + Assembly.GetExecutingAssembly().GetName().Version.ToString(3));

        // Fix tls 1.2 not supported on Windows 7 - github.com is tls 1.2 only
        try
        {
            ServicePointManager.SecurityProtocol |= SecurityProtocolType.Tls12;
        }
        catch (NotSupportedException e)
        {
            LogFile.WriteLine("An error occurred while setting up networking, web requests will probably fail: " + e);
        }

        Splash.SetText("Finding references...");
        RoslynReferences.GenerateAssemblyList();

        AppDomain.CurrentDomain.AssemblyResolve += ResolveDependencies;

        Config = PluginConfig.Load(pluginsDir);
        List = new(pluginsDir, Config);

        Config.Init(List);

        StatsClient.OverrideBaseUrl(Config.StatsServerBaseUrl);

        Splash.SetText("Patching...");
        LogFile.WriteLine("Patching");

        // Check harmony version
        var expectedHarmony = new Version(HarmonyVersion);
        var actualHarmony = typeof(Harmony).Assembly.GetName().Version;
        if (expectedHarmony != actualHarmony)
            LogFile.WriteLine(
                $"WARNING: Unexpected Harmony version, plugins may be unstable. Expected {expectedHarmony} but found {actualHarmony}");

        new Harmony("avaness.PluginLoader").PatchAll(Assembly.GetExecutingAssembly());

        Splash.SetText("Instantiating plugins...");
        LogFile.WriteLine("Instantiating plugins");
        foreach (var id in Config)
        {
            var data = List[id];
            if (data is GitHubPlugin github)
                github.Init(pluginsDir);
            if (PluginInstance.TryGet(data, out var p))
            {
                plugins.Add(p);
                if (data.IsLocal)
                    HasLocal = true;
            }
        }

        sw.Stop();

        // FIXME: It can potentially run in the background speeding up the game's startup
        ReportEnabledPlugins();

        LogFile.WriteLine($"Finished startup. Took {sw.ElapsedMilliseconds}ms");

        Cursor.Current = temp;

        Splash.Delete();
        Splash = null;
    }

    public PluginList List { get; }
    public PluginConfig Config { get; }
    public SplashScreen Splash { get; }

    /// <summary>
    ///     True if a local plugin was loaded
    /// </summary>
    public bool HasLocal { get; }

    // Skip local plugins, keep only enabled ones
    public string[] TrackablePluginIds => Config.EnabledPlugins.Where(id => !List[id].IsLocal).ToArray();

    public void Init(object gameInstance)
    {
        LogFile.WriteLine($"Initializing {plugins.Count} plugins");
        for (var i = plugins.Count - 1; i >= 0; i--)
        {
            var p = plugins[i];
            if (!p.Init(gameInstance))
                plugins.RemoveAtFast(i);
        }

        init = true;
    }

    public void Update()
    {
        if (init)
            for (var i = plugins.Count - 1; i >= 0; i--)
            {
                var p = plugins[i];
                if (!p.Update())
                    plugins.RemoveAtFast(i);
            }
    }

    public void HandleInput()
    {
        if (init)
            for (var i = plugins.Count - 1; i >= 0; i--)
            {
                var p = plugins[i];
                if (!p.HandleInput())
                    plugins.RemoveAtFast(i);
            }
    }

    public void Dispose()
    {
        foreach (var p in plugins)
            p.Dispose();
        plugins.Clear();

        AppDomain.CurrentDomain.AssemblyResolve -= ResolveDependencies;
        LogFile.Dispose();
        Instance = null;
    }

    public bool TryGetPluginInstance(string id, out PluginInstance instance)
    {
        instance = null;
        if (!init)
            return false;

        foreach (var p in plugins)
            if (p.Id == id)
            {
                instance = p;
                return true;
            }

        return false;
    }

    private void ReportEnabledPlugins()
    {
        if (!PlayerConsent.ConsentGiven)
            return;

        Splash.SetText("Reporting plugin usage...");
        LogFile.WriteLine("Reporting plugin usage");

        // Config has already been validated at this point so all enabled plugins will have list items
        // FIXME: Move into a background thread
        if (StatsClient.Track(TrackablePluginIds))
            LogFile.WriteLine("List of enabled plugins has been sent to the statistics server");
        else
            LogFile.WriteLine("Failed to send the list of enabled plugins to the statistics server");
    }

    public void RegisterComponents()
    {
        LogFile.WriteLine($"Registering {plugins.Count} components");
        foreach (var plugin in plugins)
            plugin.RegisterSession(MySession.Static);
    }

    public void DisablePlugins()
    {
        Config.Disable();
        plugins.Clear();
        LogFile.WriteLine("Disabled all plugins");
    }

    public void InstantiatePlugins()
    {
        LogFile.WriteLine($"Loading {plugins.Count} plugins");
        for (var i = plugins.Count - 1; i >= 0; i--)
        {
            var p = plugins[i];
            if (!p.Instantiate())
                plugins.RemoveAtFast(i);
        }
    }


    private Assembly ResolveDependencies(object sender, ResolveEventArgs args)
    {
        var assembly = args.RequestingAssembly?.GetName().ToString();
        if (args.Name.Contains("0Harmony"))
        {
            if (assembly != null)
                LogFile.WriteLine("Resolving 0Harmony for " + assembly);
            else
                LogFile.WriteLine("Resolving 0Harmony");
            return typeof(Harmony).Assembly;
        }

        if (args.Name.Contains("SEPluginManager"))
        {
            if (assembly != null)
                LogFile.WriteLine("Resolving SEPluginManager for " + assembly);
            else
                LogFile.WriteLine("Resolving SEPluginManager");
            return typeof(SEPMPlugin).Assembly;
        }

        return null;
    }
}